Objective To observe the effect of acupoint catgut embedment(ACE) on expression of p38 mitogen activated protein kinase(p38 MAPK)

intercellular adhesion molecule-1(ICAM-1)

interleukin-4(IL-4) and eosinophils(EOS) in lung tissue of asthmatic rats

so as to explore its mechanism underlying improvement of asthma.Methods Forty male Wistar rats were randomly divided into control

model

ACE and dexamethasone(DEX) groups

with 10 rats in each group. The asthmatic model was established by intraperitoneal injection of mixture suspension(1 mL) of ovalbumin(OVA

10%) and 10% Al(OH)_3+ normal saline

followed by inhalation of atomized 1% OVA solution for 30 min

once daily for 2 weeks to trigger occurrence of asthmatic symptoms. The ACE was applied once to “Feishu”(BL13)

“Dingchuan”(EX-B1) and “Danzhong”(CV17). Rats of the DEX group were given intraperitoneal injection of DEX once a day for 2 weeks. H.E. staining was used to evaluate histopathological changes of the lung tissue. The relative number of EOS in the bronchoalveolar lavage fluid(BALF) was detected by Wright Giemsa staining. The apoptosis level of EOS in the lung tissue was detected by TUNEL staining. The ultrastructural changes of EOS in the lung tissues were observed by transmission electron microscope(TEM). The expression of p38 MAPK

ICAM-1 and IL-4 mRNAs in the lung tissue was detected by quantitative real-time PCR.Results Findings of optical microscope and TEM showed obvious bronchial deformation and inflammatory cell infiltration

rupture of EOS cell membrane

uneven cytoplasm with swelling and uneven density of eosinophilic granules in EOS of the model group

which was relatively milder in the ACE and DEX groups. Compared with the control group

the EOS number in BALF and the expressions of p38 MAPK

ICAM-1 and IL-4 mRNAs in the lung tissue were significantly increased(P<0.01)

and the apoptosis index of EOS in the lung tissue was significantly decreased(P<0.01) in the model group. After intervention

the EOS number in BALF and expression levels of p38 MAPK

ICAM-1 and IL-4 mRNAs in the lung tissue of ACE and DEX groups were significantly decreased(P<0.01

P<0.05)

as well as the apoptosis index of EOS in the lung tissue was significantly increased in both ACE and DEX groups(P<0.01) in comparison with the model group. The EOS number in BALF and expression of ICAM-1 mRNA were significantly lower in the DEX group than those in the ACE group(P<0.05).Conclusion Catgut embedding at acupoints may alleviate the airway inflammatory response in asthma rats

which may be related with its effects in down-regulating p38 MAPK signaling

ICAM-1 and IL-4 mRNA expression

reducing the aggregation of EOS

and promoting the apoptosis of EOS.